Matrix elements of the spin-spin interactions for f sup 4 configurations
Matrix elements of spin-spin interactions for F4 electron configurations
Barnes, J. A.↗
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Extended Interacting Boson Model with Configuration Mixing Description For 98 Mo
An extended version of the interacting boson model (IBM), encompassing two-particle–two-hole (2p-2h) excitations originating from below a valence shell and one-particle–one-hole (1p-1h) excitations extending to the upper next-nearest major shell, is developed to investigate cross-shell excitation effects in the transitional nucleus 98 Mo. This extended IBM framework is utilized to reproduce experimentally observed properties such as low-lying positive-parity level energies, 𝐵(𝐸2) values, and the electric quadrupole moment of the 2$^{+}_{1}$ state, 𝜌 2 (𝐸0, 0$^{+}_{2}$ → 0$^{+}_{g}$), as well as the strength functions of the isoscalar giant monopole resonance (ISGMR) and the isoscalar giant quadrupole resonance (ISGQR) in 98 Mo. It is shown that the extended consistent-𝑄 IBM, incorporating configuration mixing of both 2p-2h excitations from below the valence shell and 1p-1h excitations to the upper next-nearest major shell, describes the low-lying structural properties and the ISGMR and ISGQR strength distributions of 98 Mo quite well, with the ISGMR and the ISGQR strength distributions comparable to the results of the self-consistent quasiparticle random-phase approximation with Skyrme interactions.
90 ≤ A ≤ 149↗
Burst vortex/boundary layer interaction
Several configurations of delta wing vortex generator and boundary layer test plate were tested, and two final ones selected. Sample measurements and flow visualizations in the candidate configurations, together with more detailed measurements in one of the two final arrangements, which were selected so that a pure vortex bursts repeatably and then interacts, in as simple fashion as possible, with a simple turbulent boundary layer, are included. It is concluded that different intensities of bursting or breakdown, like different strengths of shock wave or hydraulic jump, can be produced by minor changes of configuration. The weaker breakdowns do not produce flow reversal. The initial measurements were done with a fairly weak, but repeatable, breakdown. Basic measurements on the second final arrangement, with a stronger breakdown, are in progress.
Bradshaw, P.↗
The characteristics of the ground vortex and its effect on the aerodynamics of the STOL configuration
The interaction of the free stream velocity on the wall jet formed by the impingement of deflected engine thrust results in a rolled up vortex which exerts sizable forces on a short takeoff (STOL) airplane configuration. Some data suggest that the boundary layer under the free stream ahead of the configuration may be important in determining the extent of the travel of the wall jet into the oncoming stream. Here, early studies of the ground vortex are examined, and those results are compared to some later data obtained with moving a model over a fixed ground board. The effect of the ground vortex on the aerodynamic characteristics are discussed.
Stewart, Vearle R.↗
High flux, narrow bandwidth compton light sources via extended laser-electron interactions
New configurations of lasers and electron beams efficiently and robustly produce high flux beams of bright, tunable, polarized quasi-monoenergetic x-rays and gamma-rays via laser-Compton scattering. Specifically, the use of long-duration, pulsed lasers and closely-spaced, low-charge and low emittance bunches of electron beams increase the spectral flux of the Compton-scattered x-rays and gamma rays, increase efficiency of the laser-electron interaction and significantly reduce the overall complexity of Compton based light sources.
42 ENGINEERING↗
Aerodynamic and Acoustic Interactions Associated with Inboard Propeller-Wing Configurations
A series of aerodynamic performance and acoustic measurements have been made on a range of inboard propeller-wing interaction configurations in the NASA Langley Low Speed Aeroacoustic Wind Tunnel (LSAWT). The results presented in this paper are part of a more expansive testing campaign encompassing both single propeller-wing and multipropeller-wing interactions, the former of which is discussed in the present work. The primary testing parameters of interest to this study are the axial and vertical positioning of the wing relative to the propeller slipstream under a constant propeller advance ratio. A multi-faceted computational effort was also employed in an effort to identify reflection and scattering effects imposed by both the wing geometry as well as the primary components of the facility test setup. This effort consisted of aerodynamic predictions using high-fidelity computational fluid dynamics (CFD), acoustic predictions using an impermeable Ffowcs Williams and Hawkings (FW-H) solver, and acoustic scattering predictions. Acoustic measurements reveal variations in the acoustic directivity behavior of the propeller blade passage frequency for even modest variations in wing position. CFD-based acoustic predictions reveal discrepancies relative to the experimental data, which is believed to be due to complex acoustic scattering behavior within the test section. Initial attempts at modeling the scattered acoustic field showed functional dependency of the acoustic amplitude variations on the wing position relative to the propeller disk, however discrepancies with experimental data remain.
Nikolas S. Zawodny↗
Matrix elements of atomic interaction operators for d sup n configurations
Tabulation of matrix elements of atomic interaction operators for various configurations
Barnes, J. A.↗
Prototype System for Detecting Interactions between Current Plant Configuration States and Component Manipulations Directed by In-Use Procedures
This research effort is a part of the Light Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by the Department of Energy. The LWRS Program is performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long term, safe, and economical operation of current nuclear power plants (NPPs). The LWRS Program serves to help the United States (U.S.) nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of these NPPs and extension of their current operating licenses. The Outage Risk Management Improvement Pilot Project seeks to improve the management of nuclear power plant outages through the development of tools to assist in evaluating pending activities against requirements to detect undesired interactions. Significant efforts are expended to manage the nuclear risk of an outage. The utilities conduct pre outage risk assessments, based on a very detailed review of the outage schedule, to identify where combinations of outage work and equipment out of service would result in degraded conditions with respect to nuclear safety or regulatory compliance. Probabilistic risk assessment studies are conducted to quantify the incremental core damage frequency as a result of the outage activities and system unavailability. These studies are usually presented to site and fleet management, the site plant operational review committee, and the NPP’s independent Nuclear Safety Review Board for concurrence that the outage is planned safely and that reasonable measures have been taken to reduce the added risk of conducting the outage. During the outage, the plant configuration is monitored continuously to ensure that it conforms to the approved safety plan. Deviations must be assessed and approved by management committees and, in some cases, the plant operational review committee. In virtually all outage meetings and job briefings, the current nuclear safety status of the plant is communicated, including information on the specific equipment that is being relied on to meet the requirements of the nuclear safety plan. In addition, Operations and the Outage organizations implement several layers of physical and administrative barriers to prevent unintended interaction with the systems and equipment credited for nuclear safety. In spite of all these efforts, nuclear safety challenges still occur too frequently in outages. While some of these are due to failures of equipment credited for safety, the majority occur because of human error. These typically involve some form of interaction between work activities and plant configuration changes. Some of them are very subtle and are extremely challenging to detect in advance. Nevertheless, they are not acceptable and represent clear opportunities to improve nuclear safety during outages. This project will develop tools and strategies to minimize these interactions. This report describes a prototype tool designed to support plant personnel in controlling work during NPP outages to prevent unintended interactions. A software application was created to manage and display important configuration information and utilize natural language processing to access the impacts of upcoming procedures and work orders. Initial industry feedback is also presented.
99 GENERAL AND MISCELLANEOUS↗
Understanding the Charge Transfer at the Interface of Electron Donors and Acceptors: TTF–TCNQ as an Example
Charge transfer between an electron donor and an electron acceptor is widely accepted as being independent of their relative configurations if the interaction between them is weak; however, the limit of this concept for an interacting system has not yet been well established. Our study of prototypical electron donor–acceptor molecules, tetrathiafulvalene–tetracyanoquinodimethane, using density functional theory based on an advanced functional, clearly demonstrates that for interacting molecules, their configurational arrangement is as important as their individual electronic properties in the asymptotic limit to determine the charge transfer direction. For the first time, we demonstrate that by changing their relative orientation, one can reverse the charge transfer direction of the pair, causing the molecules to exchange roles as donor and acceptor. In conclusion, our theory has important implications for understanding the interfacial charge-transfer mechanism of hybrid systems and related phenomena.
36 MATERIALS SCIENCE↗
Technologies for Detecting Interactions between Current Plant Configuration States and Component Manipulations Directed by In-Use Procedures
This research effort is a part of the Light Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by the Department of Energy. The LWRS Program is performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long term, safe, and economical operation of current nuclear power plants (NPPs). The LWRS Program serves to help the United States (U.S.) nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of these NPPs and extension of their current operating licenses. A new area of LWRS research, Outage Risk Management Improvement (ORMI) seeks to improve the management of nuclear power plant outages through the development of tools to assist in evaluating pending activities against requirements to detect undesired interactions. Significant efforts are expended to manage the nuclear risk of an outage. The utilities conduct pre outage risk assessments, based on a very detailed review of the outage schedule, to identify where combinations of outage work and equipment out of service would result in degraded conditions with respect to nuclear safety or regulatory compliance. Probabilistic risk assessment studies are conducted to quantify the incremental core damage frequency as a result of the outage activities and system unavailability. These studies are usually presented to site and fleet management, the site plant operational review committee, and the NPP’s independent Nuclear Safety Review Board for concurrence that the outage is planned safely and that reasonable measures have been taken to reduce the added risk of conducting the outage. During the outage, the plant configuration is monitored continuously to ensure that it conforms to the approved safety plan. Deviations must be assessed and approved by management committees and, in some cases, the plant operational review committee. In virtually all outage meetings and job briefings, the current nuclear safety status of the plant is communicated, including information on the specific equipment that is being relied on to meet the requirements of the nuclear safety plan. In addition, Operations and the Outage organizations implement several layers of physical and administrative barriers to prevent unintended interaction with the systems and equipment credited for nuclear safety. In spite of all these efforts, nuclear safety challenges still occur too frequently in outages. While some of these are due to failures of equipment credited for safety, the majority occur because of human error. These typically involve some form of interaction between work activities and plant configuration changes. Some of them are very subtle and are extremely challenging to detect in advance. Nevertheless, they are not acceptable and represent clear opportunities to improve nuclear safety during outages. This project will develop tools and strategies to minimize these interactions.
99 GENERAL AND MISCELLANEOUS↗
Leveraging Interaction History for Intelligent Configuration of Multiple Coordinated Views in Visualization Tools
Visualization tools can take advantage of multiple coordinated views to support analysis of large, multidimensional data sets. Effective design of such views and layouts can be challenging, but understanding users analysis strategies can inform design improvements. We outline an approach for intelligent design configuration of visualization tools with multiple coordinated views, and we discuss a proposed software framework to support the approach. The proposed software framework could capture and learn from user interaction data to automate new compositions of views and widgets. Such a framework could reduce the time needed for meta analysis of the visualization use and lead to more effective visualization design.
infovis↗
Shock-turbulence interactions in a reacting flow
A specific reactive flow configuration, the interaction of a detonation wave with convected homogeneous isotropic weak turbulence (which can be constructed by a Fourier synthesis of small amplitude shear waves) is addressed. The effect of chemical heat release on the rms fluctuations downstream of the detonation is presented as a function of Mach number. In addition, for the particular case of the von Karman spectrum, the one dimensional power spectra of these flow quantities is given.
Jackson, T. L.↗
Sulfated glycopeptide nanostructures for multipotent protein activation
Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. Here, we report on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with very different polysaccharide binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signaling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than expected. These super-bioactive nanostructures may enable many therapies in the horizon involving proteins.
36 MATERIALS SCIENCE↗
Fission dynamics of 240Pu from saddle to scission and beyond
Calculations are presented for the time evolution of 240 Pu from the proximity of the outer saddle point until the fission fragments are well separated, using the time-dependent density functional theory extended to superfluid systems. We have tested three families of nuclear energy density functionals and found that all functionals exhibit a similar dynamics: The collective motion is highly dissipative and with little trace of inertial dynamics, due to the one-body dissipation mechanism alone. This finding justifies the validity of using the overdamped collective motion approach and to some extent the main assumptions in statistical models of fission. This conclusion is robust with respect to the nuclear energy density functional used. The configurations and interactions left out of the present theory framework only increase the role of the dissipative couplings. An unexpected finding is varying the pairing strength within a quite large range has only minor effects on the dynamics. We find notable differences in the excitation energy sharing between the fission fragments in the cases of spontaneous and induced fission. With increasing initial excitation energy of the fissioning nucleus, more excitation energy is deposited in the heavy fragment, in agreement with experimental data on average neutron multiplicities.
Bulgac, Aurel↗
Chiral Four-Wave Mixing Signals with Circularly Polarized X-ray Pulses
Chiral four-wave mixing signals are calculated using the irreducible tensor formalism. Different polarization and crossing angle configurations allow to single out the magnetic dipole and the electric quadrupole interactions. Other configurations can reveal that the chiral interaction occurs at a given step within the nonlinear interaction pathways. Applications are made to the study of valence excitations of S-ibuprofen by chiral stimulated X-ray Raman signals at the carbon K-edge and by chiral visible 2D electronic spectroscopy.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Hypersonic shock-interaction phenomena applicable to space shuttle configurations
The convective heat transfer distribution for space shuttle configurations is discussed. The viscous/inviscid interactions associated with the complex three dimensional flow fields are examined. Two basic conditions are considered as follows: (1) models consisting of basic elemental combinations and (2) models of specific flight vehicles. The test facilities and test programs used to obtain data on the fuselage flow field and the wing flow field are described.
Bertin, J. J.↗
Quasi-three-dimensional laminar boundary-layer separations in supersonic flow
A numerical algorithm is presented for solving laminar, steady, supersonic interacting boundary-layer flows for quasi-three-dimensional configurations. The interaction problem is treated as a boundary-value problem and a salient feature of the scheme is the direct implementation of the downstream boundary condition. Solutions are presented for axisymmetric and swept (yawed) compression ramps for both adiabatic and heat transfer conditions over a Mach number range of 2-6. The results are in good agreement with experimental data and existing theories for axisymmetric cases. For the swept (yawed) configurations, lack of experimental data makes a direct comparison impossible, but the present solutions are found to be in qualitative agreement with earlier studies. In addition it is shown that the trends obtained here for the sweep effects are well predicted by a simple extension of the two-dimensional asymptotic theory.
Vatsa, V. N.↗